How things went wrong in Metrolink train crash

Shortly before 4:23 p.m. on Friday, a dispatcher in a remote Metrolink control room tried desperately to reach the crew of Train 111.

A flashing error message popped up on a computer screen, signaling that something went wrong near a stretch of track where Metrolink engineer Rob Sanchez was supposed to stop at a rail signal.

A dispatcher, fearing the worst, put in an urgent call to let Sanchez know he might have run a red light. The call came in, but it was too late: The worst commuter train crash in Los Angeles' history had already occurred.

And the blame seemed to point squarely at Sanchez.

"We believe our engineer was on the main track and failed to stop," Metrolink spokeswoman Denise Tyrrell said Saturday.

The National Transportation Safety Board is zeroing in on the communications between the driver, conductor and dispatchers, and examining the electronic signaling systems.

But experts say even if the NTSB pins the blame on the driver, the horrific crash still reveals serious problems in the commuter line's warning system.

Some say there was too little time between the critical moment when the driver ran the red signal and when dispatchers in Pomona learned that the train was heading directly toward an oncoming Union Pacific freight train. And there may not have been enough warning signals alerting the driver to stop.

"This is just the tip of the iceberg. We really should look at the whole system," said Najmedin Meshkati, an expert in human error and large-scale technological systems with the University of Southern California.

The Metrolink commuter train runs along more than 400 miles of mostly single-line tracks shared with freight trains like the six-car Union Pacific train that derailed Friday.

The right of way on the stretch between Union Station in Los Angeles and Moorpark, where Train 111 was traveling, is controlled by Metrolink dispatchers.

Those dispatchers set the lights telling drivers which train should stop or go during passes on a short two-mile, two-line track. They also remotely control switching lines so the train with the right of way is diverted to the empty track.

"There are safety features built in," said Metrolink spokesman Francisco Oaxaca, who identified Sanchez as the train's engineer. "There is software that blocks dispatchers from sending a signal that would cause a collision."

Friday, dispatchers activated a pair of warning signal lights spaced about two-thirds of a mile apart from each other. All systems appeared to be normal and functioning properly.

Sanchez would have come upon the first light shortly after leaving the Chatsworth station; it would have warned him not to continue barreling toward the impending disaster.

Oaxaca said the signal likely showed a yellow warning sign for the train to slow down. To ensure the engineer who is driving the train is paying attention, Metrolink requires him to radio a conductor walking through the train to check tickets and help passengers. It's unclear whether that occurred; Sanchez was one of those killed in the crash.

About two-thirds of a mile after the first warning light, not far from where the crash occurred, the engineer would have approached the second signal. All Metrolink indicators show that the signal would have been red at the time.

"We don't know how this error happened, but this is what we believe happened," Tyrrell said.

But Meshkati argues that if there had been an audio signal as well as a red light, the accident could have been prevented.

"I commend their straightforwardness," he said. "But this is what I call blaming the victim and oversimplification of the problem. Why did he fail (to stop). Did he just simply overlook this? Did he fall asleep? What other systems ... should have been in place and warned him?"

The NTSB has previously urged the Federal Railroad Administration to require systems that could override human error. Other experts say it may have just been a matter of geography and speed. The collision occurred just around the bend of a sharp turn.

"I was profoundly surprised," said Jim Moore, director of the Transportation Engineering program at USC. "It says to me that in that location operating procedures ought to change. I don't know exactly how. But it may be as simple as speed."